Multiple Objects don't move correctly in same armature
Thanks for your support, I did it.

I think it were in fact, the vertex weight, since there still was weigth from nearby bones on the skull and the jaw bone. I resetted the whole groups and edited the weight of every bone for the skull and the jaw, so it's mainly on 100% for the resperctive bones and 0 for the others.





Upper teeth and eyes weight was set 100% only to the skull bone and lower teeth was set 100% only to the jaw bone.

Thanks again for your help!
Johann